JP5517020B2 - Aluminum laminated tube container - Google Patents

Description

  The present invention relates to a tube container that exhibits high gas barrier properties using an aluminum laminate sheet.

  As a sheet material that exhibits an excellent gas barrier property, an aluminum laminate sheet in which both sides of an aluminum foil are covered with a synthetic resin layer is known, and a tube container in which a body portion is formed by winding an aluminum laminate sheet is widely used. Yes.

  This tube container is extremely excellent in the gas barrier property of the body part, which is the main part of the container, but the head part connected to the body part is formed of a synthetic resin material by compression molding or injection molding. Therefore, the gas barrier property is low, and there is a disadvantage that the gas barrier property of the entire container is lowered.

  As a conventional technique for solving this inconvenience, for example, as shown in Patent Document 1, a technique of laminating a barrier sheet piece made of an aluminum laminate sheet on a shoulder portion of a head portion formed of a synthetic resin material has been proposed. Yes.

That is, when molding the head portion with a synthetic resin material, a ring-shaped barrier sheet piece is placed as an insert material in the core mold when the head portion is molded, and this barrier sheet piece is molded into the head portion. While pressing against the mold surface with a synthetic resin material
It is integrally welded to the inner peripheral surface of the head portion.
JP 2002-225057 A

  In this conventional technology, since the layer of the aluminum laminate sheet can be provided also on the shoulder portion of the head portion connected to the body portion made of the aluminum laminate sheet, the gas barrier property of the head portion can be improved. A tube container having a sufficiently high gas barrier property can be obtained.

  However, in the configuration in which the barrier sheet pieces are laminated on the inner peripheral surface of the conventional head part, the head part is formed in a state where the ring-shaped barrier sheet piece is pressed onto the mold surface. There was a problem that the adhesive strength between the head resin portion made of synthetic resin and the end face of the barrier sheet piece was not sufficient.

  That is, as shown in FIG. 6, the end surface of the barrier sheet piece 6a and the head resin portion 4 have a small area on the end surface of the barrier sheet piece 6a, and a sufficient welding strength cannot be obtained. In the joining part Sa on the outer peripheral end face side of the piece 6a, there is a problem that sufficient welding strength cannot always be obtained due to the action mode of the fluid pressure when the molten resin flows when the head resin portion 4 is molded.

  As described above, since the welding strength at the joint portion Sa is not sufficient, and the portion where the joint portion Sa is located is the peripheral end portion of the shoulder portion of the tube container, the deformation force is exerted by the contact with another article. By being easy to receive, this joint part Sa peels off easily, the aluminum foil layer of the barrier sheet piece 6a is exposed in the container, and the contents enter the peeled joint part Sa. There is a problem that the barrier sheet piece 6a is peeled off from the peeled joint site Sa as a starting point and the barrier performance is lowered.

  Therefore, the present invention has a technical problem to create a laminated structure of barrier sheet pieces that can stably and reliably exhibit barrier performance in the head portion of an aluminum laminated tube container.

Among the means for solving the above problems, the main configuration of the present invention is:
In the aluminum laminate tube container in which the head part with the mouth tube part erected from the upper end opening part of the cap-shaped shoulder part is heat-welded and fixed to the upper end of the barrel part in which the aluminum laminate sheet is cylindrical,
A ring-shaped barrier sheet piece made of an aluminum laminate sheet in which the head portion is laminated by thermal welding on a region from the upper end portion to the lower end portion of at least the outer peripheral surface of the shoulder portion of the head resin portion. And having a configuration
The outer resin layer and inner resin layer of the aluminum laminate film forming the body and the four resin layers of the outer resin layer and inner resin layer of the aluminum laminate film forming the barrier sheet piece are made of the same type of synthetic resin so that they can be heat-welded. ,
The barrier sheet piece as an insert member disposed in a portion corresponding to the shoulder of the cavity mold, a molten resin according to the head resin portion on a piece barrier sheet supplied mounted, the core metal of the body portion is fitted in advance The barrier sheet piece shall be laminated on the head part by compression molding or injection molding of the head part to insert the mold into the cavity part of the cavity mold,
Compared to the barrier sheet piece, the body is made of thick aluminum laminate sheet,
Laminate the upper end of the body part to the lower end part of the head resin part by heat welding in an outer fitting shape,
On the outer peripheral surface of the head resin portion, the lower end surface of the barrier sheet piece and the upper end surface of the body portion are in contact with each other with the head resin portion being lined by thermal welding from the inside, and joined,
It is said that the barrier sheet piece and the outer peripheral surface of the body portion are configured to be flush with each other with a joint portion between the lower end surface of the barrier sheet piece and the upper end surface of the body portion interposed therebetween.

The characteristic of the said structure exists in the point which laminated | stacked the barrier sheet piece on the inner peripheral surface of the shoulder part of a head resin part on the outer peripheral surface conventionally.
Here, in the process of forming the head part and thermally welding and fixing to the body part, a ring-shaped barrier sheet piece is placed in advance as an insert material at a position corresponding to the shoulder part of the cavity mold, and compression molding or injection molding is used. In the state where the lower end surface of the barrier sheet piece and the upper end surface of the barrel portion are in contact, the barrier sheet piece and the upper end portion of the barrel portion are pressed against the cavity mold by the pressure of the molten resin, and the resin head portion is molded. By doing so, the head portion can be heat-welded and fixed to the upper end portion of the cylindrical body portion with the above-described configuration of the present invention.

  Then, as described above, by laminating the barrier sheet piece on the outer peripheral surface of the shoulder portion of the head resin portion, even if the bonding area between the lower end surface of the barrier sheet piece and the upper end surface of the body portion is small, the head resin The two parts can be firmly bonded to each other by thermal welding from the inside, and the barrier effect of the aluminum foil layer can be continuously and stably exhibited from the body part to the shoulder part.

In addition, by forming the body part from a thick aluminum laminate sheet compared to the barrier sheet piece, in the formation of the head part using the barrier sheet piece as an insert material, the lower end surface of the barrier sheet piece and the upper end surface of the body part Can be reliably realized.

Moreover , by making the outer peripheral surface of the barrier sheet piece and the trunk portion flush with each other across the joining portion of the lower end surface of the barrier sheet piece and the upper end surface of the trunk portion, a good appearance can be obtained. Further, it is possible to effectively prevent the peeling of the one end portion of the barrier sheet due to the step.

Since the present invention has the above-described configuration, the following effects can be obtained.
That is, in what has the main structure of this invention, by joining a barrier sheet piece on the outer peripheral surface of the shoulder part of a head resin part, even if the lower end surface of a barrier sheet piece and the upper end surface of a trunk | drum are joined. Even if the area is small, the head resin part can be backed by heat welding from the inside to firmly bond them together, and the barrier effect by the aluminum foil layer is continuously and reliably from the body part to the shoulder part. Can be demonstrated.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below along the examples with reference to the drawings.
1 to 4 show an embodiment of an aluminum laminated tube container according to the present invention. FIG. 1 is a half vertical sectional view showing the configuration near the head portion of the tube container, and FIG. 2 is a circle in FIG. 3 is an enlarged cross-sectional view of the region indicated by A, FIG. 3A is a plan view and FIG. 4B is a vertical cross-sectional view of the barrier sheet piece 6 used in the tube container of FIG. 1, and FIG. 4 is the barrier shown in FIG. 3 is a cross-sectional view showing a laminated structure of sheet pieces 6. FIG.

  This tube container is a short tube in which a thread is engraved on the outer peripheral surface of the upper end of the barrel-shaped shoulder 2 at the upper end of the barrel 12 formed by winding the aluminum laminate sheet 13 into a cylindrical shape. A head portion 1 provided with a cylindrical mouth tube portion 3 is fixed by heat welding.

  As shown in the enlarged view of FIG. 2, the aluminum laminate sheet 13 constituting the body 12 is configured by laminating an outer resin layer 15, an adhesive resin layer 17, an aluminum foil layer 14, and an inner resin layer 16 in order from the outside. The outer resin layer 15 has a thickness that can secure the mechanical strength required by the body portion 12, and the adhesive resin layer 17 firmly bonds the aluminum foil layer 14 and the outer resin layer 15, In general, polyethylene (PE) resin is suitable for the outer resin layer 15 and the inner resin layer 16 in terms of strength, content resistance, flexibility, moldability, and the like.

  The head portion 1 forms a skeleton from the mouth tube portion 3 to the shoulder portion 2, that is, on the outer peripheral surface from the upper end of the shoulder portion 2 of the head resin portion 4 to the lower end portion. It is made of an aluminum laminate sheet, and is formed by laminating ring-shaped and cap-shaped barrier sheet pieces 6 (see FIG. 3) by heat welding.

  Since the head resin portion 4 is fixed to the barrel portion 12 by heat welding, the head resin portion 4 is made of the same kind of synthetic resin as the outer resin layer 15 and the inner resin layer 16 of the barrel portion 12, but has high content resistance and high moldability. Therefore, the use of PE resin is suitable.

The layer structure of the barrier sheet piece 6 is as shown in FIG. 4, and a reinforcing resin layer 9 made of polyethylene terephthalate (PET) resin or the like for imparting rigidity is laminated on the upper side of the aluminum foil layer 7, and this aluminum foil layer 7 and the reinforcing resin layer 9 have a layer structure in which the outer resin layer 8 and the inner resin layer 10 are respectively laminated on the outer surface and the inner surface of the laminate.
Further, the outer resin layer 8 and the inner resin layer 10 are of the same type as the head resin portion 4 in consideration of the heat-weldability with the upper end surface of the body portion 12 in the head resin portion 4 and also in the joining portion S (see FIG. 2). The synthetic resin is made of PE resin in this embodiment.

  Further, the barrier sheet piece 6 is formed by punching from an aluminum laminate sheet, and simultaneously with this punching, the aluminum foil layer 7 is plastically deformed to form a shade as shown in FIG. The thickness is about 20 to 60 microns so that the shade shape returns to a flat shape and does not deform.

Next, FIG. 5 is a schematic explanation showing an example of a step of thermally welding and fixing the head portion 1 to the upper end portion of the body portion 12 at the same time as forming the head portion 1 in the tube container of the above-described embodiment.
A barrier sheet piece 6 formed by punching from the above-mentioned aluminum laminate sheet into a ring shape and a shade shape is disposed as an insert material at a position corresponding to the shoulder of the cavity mold 32, and the barrier sheet piece 6 is placed on the barrier sheet piece 6. Then, the molten resin P made of PE resin cut out in a donut shape from the injection nozzle is supplied and mounted.

Then, the core mold 31 having the body portion 12 fitted into the cavity portion of the cavity mold 32 is inserted, and the molten resin P is flowed in a pressing state to form the head resin portion 4, and at the same time, the lower end of the head portion 4. The head portion 4 and the upper end portion of the body portion 12 are heat-welded, and the head portion 4 is heat-welded and fixed to the upper end portion of the body portion 12, and the barrier sheet piece 6 that is an insert material is attached to the outer peripheral surface of the shoulder portion 2 of the head resin portion 4. In addition, they are laminated together by heat welding.
Here, the core mold 31 is finally inserted to a position indicated by a two-dot chain line in the cavity mold 32.

Then, the upper end portion of the body portion 12 is laminated on the lower end portion of the head resin portion 4 by heat welding as shown in FIG.
In addition, on the outer peripheral surface of the shoulder portion 2 of the head resin portion 4, the barrier sheet piece 6 is firmly lined in a heat-welded shape from the inside by the head resin portion 4 by the pressing force of the molten resin at the time of molding. The lower end surface and the upper end surface of the body portion 12 are in contact with each other and joined.

  Further, the outer resin layer 8 and the inner resin layer 10 of the barrier sheet piece 6 and the outer resin layer 15 and the inner resin layer 16 of the aluminum laminate sheet 13 forming the body 12 are all made of PE resin, and the barrier sheet piece. The lower end surface of 6 and the upper end surface of the body portion 12 are joined by thermal welding at the joining portion S, and the lower end portion and the body of the barrier sheet piece 6 are coupled with the backing by the thermal welding of the head resin portion 4 described above. The upper end portion of the portion 12 can be firmly joined, and the barrier effect by the aluminum foil layer can be continuously and reliably exhibited from the trunk portion 12 to the shoulder portion 2.

  In addition, according to the above-described head portion molding and heat welding fixing step, the outer peripheral surfaces of the barrier sheet piece 6 and the body portion 12 can be brought into a flush state with no step between the joining portion S, and there is no step difference. While being able to make it an external appearance, peeling of the edge part of the barrier sheet piece 6 resulting from a level | step difference can be prevented effectively.

  In this embodiment, the body 12 is made of a relatively thick aluminum laminate sheet 13 as compared with the barrier sheet piece 6. By doing so, the head 1 shown in FIG. 5 is molded and heat-welded. In the fixing step, contact between the lower end surface of the barrier sheet piece 6 and the upper end surface of the body portion 2 can be achieved smoothly and more reliably.

As mentioned above, although embodiment of this invention was described along the Example, this invention is not limited to the said Example.
For example, the layer configuration of the barrier sheet piece is not limited to the above-described embodiment, and the pearl-like shape is taken into consideration in terms of ease of molding into a cap-shaped shape and thermal weldability with the head resin portion and the trunk portion. It is also possible to have a layer configuration in consideration of decorating properties, for example, by laminating layers having a glossiness of 2 mm.
Moreover, in the said Example, it was set as the structure which laminates | stacks a barrier sheet piece on the shoulder part outer peripheral surface of a head resin part, However It can extend further upwards and can also be laminated | stacked also on a partial area | region of a mouth tube part.

  As described above, according to the present invention, a barrier sheet piece is laminated on the outer peripheral surface of the shoulder portion of the head portion, so that the barrier effect by the aluminum foil layer is continuously formed from the trunk portion to the shoulder portion. It can be used stably and reliably, and it can be expected to be widely used for aluminum laminated tube containers.

It is a semi-longitudinal sectional view of the vicinity of the head portion showing an embodiment of the tube container of the present invention. FIG. 2 is an enlarged cross-sectional view of a region indicated by a circle A in FIG. 1. It is (a) top view and (b) longitudinal cross-sectional view of the barrier sheet piece used for the tube container of FIG. It is sectional drawing which shows the laminated structure of the barrier sheet piece of FIG. It is a schematic explanatory drawing which shows an example of a shaping | molding of the head part in the tube container of FIG. 1, and a heat welding fixing process. It is a semi-longitudinal sectional view in the vicinity of the head portion showing an example of a conventional tube container.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Head part 2; Shoulder part 3; Mouth part 4; Head resin part 6, 6a; Barrier sheet piece 7; Aluminum foil layer 8; Outer resin layer 9; Reinforcement resin layer 10; Aluminum laminate sheet 14; aluminum foil layer 15; outer resin layer 16; inner resin layer 17; adhesive resin layer 31; core mold 32; cavity mold S, Sa;

Claims (1)

The head portion (1), in which the mouth tube portion (3) is erected from the upper end opening portion of the cap-shaped shoulder portion (2), is heat-welded and fixed to the upper end of the barrel portion (12) formed of the aluminum laminate sheet. In aluminum laminated tube container,
The head portion (1) is divided into a head resin portion (4) serving as a base material of the head portion (1), and an area extending from an upper end portion to a lower end portion of at least a shoulder outer peripheral surface of the head resin portion (4). It is made of an aluminum laminate sheet laminated by heat welding and has a ring-shaped barrier sheet piece (6),
The outer resin layer (15) and inner resin layer (16) of the aluminum laminate film forming the body (12) and the outer resin layer (8) and inner resin of the aluminum laminate film forming the barrier sheet piece (6) The four resin layers of layer (10) are made of the same kind of synthetic resin so that they can be heat welded,
The barrier sheet piece (6) arranged in the portion corresponding to the shoulder (2) of the cavity mold and the insert material (32), said head resin portion on the barrier sheet piece (6) to (4) Compression molding or injection of the head part (1) in which the molten resin is supplied and placed, and the core mold (31) in which the body part (12) is preliminarily fitted is inserted into the cavity part of the cavity mold (32). The barrier sheet piece (6) is laminated on the head part (1) by molding,
Compared to the barrier sheet piece (6), the body (12) is made of a thick aluminum laminate sheet,
The upper end portion of the body portion (12) is laminated to the lower end portion of the head resin portion (4) by heat welding in an outer fitting manner,
On the outer peripheral surface of the head resin portion (4), the lower end surface of the barrier sheet piece (6) and the upper end surface of the trunk portion (12) are backed by heat welding from the inside on the head resin portion (4). Abut, join,
The outer peripheral surface of the barrier sheet piece (6) and the body portion (12) is flush with the stepped portion (S) between the lower end surface of the barrier sheet piece (6) and the upper end surface of the body portion (12). Aluminum laminated tube container with the structure

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